The microelectronic industry relies on a variety of different processes to manufacture microelectronic devices. Many processes involve a sequence of treatments in which different kinds of treatment fluids are caused to contact the workpiece in accordance with desired recipes. These fluids may be liquids, gases, or combinations thereof. In some treatments, solids may be suspended or dissolved in a liquid or entrained in a gas.
Innovative tools for processing microelectronic workpieces are described in Assignee's issued U.S. Pat. No. 7,681,581 (hereinafter Assignee's Patent No. 1) as well as in Assignee's co-pending U.S. patent applications now published as U.S. Patent Publication Nos. US-2007-0245954-A1 (hereinafter referred to as the Co-Pending Application No. 1); 2008-0271763-A1 (bearing Application No. 2); US-2008-0008834-A1 (hereinafter referred to as Co-Pending Application No. 3); 2009-0038647-A1 (hereinafter referred to as Co-Pending Application No. 4); and 2009-0280235-A1 (hereinafter referred to as Co-Pending Application No. 5). The entireties of the '581 patent and of these co-pending U.S. patent applications are incorporated herein by reference for all purposes.
The embodiments of the processing sections of these tools as described in the '581 patent cited above and in the co-pending U.S. patent applications cited above advantageously include nested duct features that allow one or more duct pathways to be selectively opened and closed. For example, when the structures are moved apart relatively, a duct pathway opens and is enlarged between the structures. When the structures are moved together relatively, the duct between the structures is choked and is reduced in size. In preferred embodiments, multiple ducts can exist in the same volume of space depending upon how the moveable duct structures are positioned. Thus, multiple ducts can occupy a volume minimally larger than the volume occupied by only a single duct. The ducts are used to capture various treatment fluids, including liquid and/or gases, for recycling, discarding, or other handling. Different treatment fluids can be recovered in different, independent ducts to minimize cross-contamination and/or to use unique capture protocols for different fluids. Because of the nested character of the duct structures, the duct system also is extremely compact.
The '581 patent cited above and the co-pending U.S. patent applications cited above also describe an innovative spray nozzle/barrier structure. This structure includes capabilities for dispensing treatment materials in multiple ways such as by a spray, a center dispense, and gas or vapor introduction. The barrier structure overlies the underlying workpiece. The lower surface of the barrier structure is shaped in preferred embodiments so that it defines a tapering flow channel over the workpiece. This approach offers many benefits. The tapering flow channel helps to promote radial flow outward from the center of the workpiece while minimizing recirculation zones. The taper also helps to smoothly converge and increase the velocity of flowing fluids approaching the outer edge of the workpiece. This helps to reduce liquid splash effects. The angle of the lower surface also helps liquid on the lower surface to drain toward the outer periphery. The tapering configuration also helps to reduce recirculation of particles back onto the workpiece. The configuration also helps facilitate chemical reclaim efficiency by better containment of fluids.
Notwithstanding all these benefits, further improvements are still desired. Firstly, during the course of treating a workpiece, the lower surface of the barrier structure may bear drops or films of liquid(s) used during the treatment and/or as a result of rinsing the barrier structure. For example, Assignee's Co-Pending Application No. 3 describes a rinsing strategy in which rinse tubes are led downward through a chimney leading into a process chamber, wherein the chimney provides a path of egress into the process chamber generally through a central region of the barrier structure. The rinse tubes extend into the process chamber so that their lower ends are generally at the same height as the lower surface of the barrier structure. A rinsing liquid is sprayed onto the lower surface through nozzles attached to the ends of the tubes. Assignee's Co-Pending Application No. 4 describes using a rinse manifold to generate a flow of rinse liquid on surfaces upstream from the process chamber. The rinse liquid is conveyed smoothly along these surfaces and then wets the underside of the barrier structure.
While these strategies effectively rinse the barrier structure, the resultant rinsing action may have more tendencies than desired to splash or drip when impacting the barrier structure. This can generate droplets or mists that, in turn, can lead to particle contamination on the underlying workpiece. Also, the alignment and dispense pattern of the rinses in either strategy can be more difficult to set up. The tubes and nozzles can collect moisture, which can drip and cause contamination. The tubes and nozzles can also obstruct and/or disrupt the flow of liquids and gases into the process chamber. Improved rinsing methodologies are therefore desired.